1. Field of the Invention
This invention relates to pelleted seed and to processes for their production, and more particularly, to pelleted seed having enhanced protection from soil-borne phytopathogenic fungi.
2. Description of the Prior Art
For some years, it has been of considerable interest to mechanize or automate the planting and cultivating of seeds so that increased production and lower labor costs may be realized, especially in large scale agricultural, horticultural and reforestation operations. Mechanical planters are now in use which efficiently and precisely place single seeds into soil at a predetermined depth and interval (which may vary according to seed type) thereby reducing the need for such subsequent labor-intensive procedures as thinning. While the use of mechanical planters has become widely accepted for planting seeds of relatively large and regular shape, e.g., corn and the like, many vegetable seeds in the natural state are ill-suited for mechanized planting due to their physical form. The small size and/or irregular shape of lettuce, sugarbeet, celery and other seeds tends to cause jamming and packing of the feeding component of mechanical planters currently in use. Heretofore, it has been a practice to adapt these seeds for mechanical planting by coating them with a composition which increases their dimensions and/or smooths their surface. In order to improve the viability of the seeds, anti-fungal agents have been incorporated into the coating composition to protect the seeds from phytopathogenic fungi present in the soil during the germination and emergence periods. To the extent such anti-fungal agents fail to perform, it becomes necessary to plant an excess of seed if a satisfactory crop yield is to be obtained from a given area of land. Overplanting will require that the young crop be thinned back to an optimum population. Thinning is an expensive hand labor operation and reduces the economies to be gained by mechanized planting. Accordingly, it is highly desirable that the viability of coated seed be maintained at as close a level to maximum as possible so as to avoid or reduce the necessity of overplanting and subsequent thinning.
Illustrative of known coated seeds which may contain a biocide as a component of their coating compositions are those described in U.S. Pat. Nos. 2,651,883; 3,545,129; 3,598,565; 3,698,133; and 3,905,152. However, in none of the coating compositions of the foregoing patents is there suggested the combination of a non-phytoxic hydrophobe and an anti-fungal agent specific in its activity against soil-borne phytopathogenic fungi.